


All This Humanity

by xylodemon



Series: deancas codas: season ten [6]
Category: Supernatural
Genre: Episode Related, M/M, Mark of Cain
Language: English
Status: Completed
Published: 2014-12-07
Updated: 2014-12-07
Packaged: 2018-02-28 11:12:06
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 5,520
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/2730257
Author URL: https://archiveofourown.org/users/xylodemon/pseuds/xylodemon
Summary: <blockquote class="userstuff">
              <p>Dean takes a deep breath, flexes his hand until the angry itch beneath his skin fades away.</p>
            </blockquote>





	All This Humanity

**Author's Note:**

> Episode/Promo tag; spoilers for 10x08 and the teasers for 10x09.
> 
> Warnings for canon-typical violence in relation to the Mark of Cain.

The Mark stirs as Dean stashes the machetes in the trunk. It's different than before, a dull throb under the scar instead of a searing ache all up and down his arm, but it's there, and that's enough to leave Dean with a tense feeling in his gut. Whatever mojo Sam and Cas worked has kept a lid on it the last few weeks, but pressure is starting to build and it's only a matter of time before the whole things blows.

Dean takes a deep breath, flexes his hand until the angry itch beneath his skin fades away. He has been staring monsters in the face since he was old enough to hold a gun, but his dad had played his own nightmares and regrets close to the vest, never told Dean what to do when the problem is the guy looking back at you in the mirror.

He isn't afraid of dying. He's afraid that he _won't_. That the next time he takes a knife will be just like the last time. That the lights won't actually go out, that they'll brighten and sharpen into shades of gray, just like they did whenever his eyes burned black and his mouth filled up with ash.

 

+

 

"All I know is back there, killing those vamps -- I felt like me again."

"All right," Sam says, frowning a little. "So that's good, right?"

"Yeah."

Dean can tell Sam doesn't believe him. They've lived together in a car for nearly all of Sam's life; he usually smells the bullshit before Dean even starts shoveling, but that's never stopped Dean from trying.

 

+

 

They crash at Donna's place for the night, Sam in the guest bedroom and Dean on the couch in the den. Dean would've been okay to drive at least three or four hours -- in fact, it might've done him some good, given him a chance to clear his head -- but pushing through would've meant grabbing a shit motel in Minneapolis or St. Paul.

Donna's couch is old enough to go with Dean's weight instead of fighting against it, and the blankets are soft; they smell like Tide, not off-brand, industrial-strength detergent. Dean can't settle -- the Mark is quiet but everything else inside him isn't -- and he stares at the shadowed shape of Donna's coffee table for what feels like half the night.

When he finally drops off, he dreams in red and black.

He doesn't know where he is, or why he has a knife, but he slices through the people around him without a second thought. He slits a guy's throat from ear to ear, lays another one open from navel to neck, jabs the knife into some chick's back so that the blade snaps clean through her spine. The bodies hit the floor with dull, heavy sounds, and blood runs warm over his hands, dries sticky and dark between his fingers. The stench of sulfur crowds into his nose and pushes down his throat until he's coughing just to breathe.

He wakes in the thin light of dawn, shaking, his skin tacky and hot where he's sweated through his shirt, the Mark thrumming on his arm like a second heartbeat.

 

+

 

Cas calls an hour into a boring stretch of I-35, says, "Hello, Dean," before Dean really has the phone up to his ear.

"Hey, man. What's up?"

"I -- um." Cas hesitates, rattles out a heavy sigh. "Where are you?"

"Northern Iowa."

"Are you hunting?"

"No," Dean says, shifting the phone closer to his ear. "We just finished up. We cleaned out a vamp nest in Minnesota." He hears a low whistle on Cas' end of the line, like he's driving with the window open. "What's -- are you okay?"

Cas sighs again, barely louder than the noise inside his car. "I'm fine, but I need your help with something."

"Okay, yeah. Where are you?"

"Pontiac, Illinois."

It's the last place Dean wants to go, except Lawrence, but Cas is asking, so Dean swings east on I-80 when he reaches Des Moines.

 

+

 

"Cas," Dean says, lowering his voice so the other customers don't overhear. They're in a diner on the edge of town, the kind of place with checkered tablecloths and an all-day blue plate special. "I need you to promise me something."

"Of course."

And that stings a little, how easily Cas agrees, because Dean knows he's pulling a dick move, that he's using their friendship and Cas' tendency to trust him to back Cas into a corner. "If I do go darkside, you gotta take me out."

"What do you mean?"

"Knife me, smite me, throw me into the freaking sun -- whatever. And don't let Sam get in the way, because he'll try."

Cas opens his mouth, closes it. A sad, frustrated wrinkle creases the space between his eyebrows, and it's so fucking human Dean has to look away. He knows he's being an asshole, but he also knows this is necessary -- so necessary that he makes himself follow through.

"I can't go down that road again, man." Dean doesn't remember much about being a demon, not in a day-to-day way, but he does remember the killing. The blood on his hands, the furious heat burning in his arm. Every body had belonged to a demon, but some had probably still had a human inside them, and he had let Crowley feed them to him like he was some kind of pet, just another one of his slavering hellhounds. "I can't be that... _thing_ again."

"Dean -- "

"Cas, please," Dean says, pitching his voice low so it doesn't crack. He grabs Cas' wrist, lets his thumb curl against Cas' palm, and -- fuck. His hand is shaking. He can scarcely admit this part to himself, has always been too cowardly to admit it to Cas. "Please."

Cas looks down at their hands, at where Dean's fingers are tucked inside the sleeve of his coat. "Fine. If you lose yourself again, I will... deal with it. But I would prefer it if we removed Cain's curse before it comes to that."

 

+

 

Claire is seventeen and reckless, sweet one minute and bristling with hollow anger the next. Dean isn't the least bit surprised when she bolts; he'd told Cas she'd probably try it, but Cas had been so hellbent on helping her that he hadn't been willing to listen.

It takes them four days to find her, couch-surfing with the friend of a friend of a friend. She lets Cas drag her out to the Impala without a fight, but she glares murder at him, looks like she'd jump out and run if Dean would just make a full and complete stop.

He rolls through every stop sign between the friend's house and the highway.

"You're not my father," she snaps, about a hundred miles outside of town.

"You're right, I'm not. But your father was a good man, and he gave his life so I could complete a mission that turned out to be false. I owe him a debt, and helping you is the only way I can repay it."

 

+

 

Jody has enough on her plate, so they take Claire to Krissy's place in Conway Springs.

Dean supposes it's better than the alternatives -- stashing her at the bunker with two dudes who couldn't stop demons from destroying her family; letting her crisscross the country with the guy who stole her father's face -- but it still feels like a failure.

Like another kid who will end up chopping the heads off vamps and ghouls instead of living her life.

 

+

 

"I told you," Sam says tiredly, gathering up all the books so he can haul them back down to the basement. "There's nothing here about the Mark."

Dean had told Cas too, but he had insisted on seeing for himself.

He's quiet for a few seconds, frowning in a way that's wholly human. Then, sighing, he says, "I'm not surprised. Cain was cursed and exiled many thousands of years ago, long before humans learned the art of written language. What's in the bible is the result of oral tradition."

"There isn't much there." Sam pauses in the doorway, the books propped between his hip and the frame. "Cain's story only gets about ten verses and the Mark is barely mentioned at all."

"It wouldn't be," Cas says, shaking his head. "Over time, Cain's story became a cautionary tale, a reminder of what could happen to those who defied god. To the people telling it, the Mark wasn't important, beyond being part of Cain's punishment." 

Dean rubs the Mark through his sleeve. "They only cared that he got what was coming to him."

"Yes. I had hoped" -- he sighs, his mouth twisting slightly. "Never mind. It was foolish."

"What?" Sam asks. "What was foolish?"

"The angel Ezekiel -- the real Ezekiel" -- Cas frowns again, darting an uncertain glance at Sam -- "he wrote a true account of Cain's marking and banishment shortly before the birth of Christ. It's likely been lost after all this time, but if it has survived, this is one of the few places it might be."

Dean sits up a little. "Where else?"

"The Vatican. The Rockefeller Museum in Jerusalem. A private collection in Damascus, assuming the man's grandchildren haven't -- "

"So, nowhere we can get to."

"It doesn't matter," Cas says stubbornly. Sam leaves the room, the books tucked under his arm, and Cas reaches across the table for Dean's wrist, touches Dean the way Dean had touched him at the diner. "We will find another way."

 

+

 

The next morning, Sam finds an internet article about two mutilated bodies at a Wyoming park. Last night had been a full moon, so they start packing up the car right after breakfast.

Cas asks if he can ride along, and he seems so pleased when Dean says yes that a joke about playing hooky from heaven dies in the back of Dean's throat. Dean doesn't know why Cas is alone again; he hasn't said much, except that the angel he'd been working with had decided to go back upstairs. That's probably for the best -- Cas is worth a thousand of those feathered dicks, and Dean is selfish enough to admit he likes having Cas around, at least to himself -- but it still makes Dean a little bit angry. They'd been happy enough to let Cas lead them when they needed it, and now it seems like they've abandoned him right when he needs something in return.

It's the easiest hunt they've had in ages; Cas catches the werewolf's scent at the dump site and tracks it straight back to her condo. They find her curled up in her bed, sleeping off her lunar hangover with blood streaking her hands, smeared around her mouth.

Dean puts three bullets into her. He makes himself stop there, bites the inside of his cheek to keep his finger from squeezing the trigger again.

 

+

 

They grab a motel outside Caspar in Glenrock; when Dean gets back from his beer run, he finds Sam knocked out on one of the beds and Cas sitting at the kitchen table, frowning as he pecks out a text on his phone.

"You talking to Claire?" Dean asks.

"Yes," Cas says, without looking up. "I wanted to know how she's settling in with Krissy and Aiden and Josephine."

"What did she say?"

Sighing, Cas tucks his phone into the pocket of his coat. "She told me to shove it."

"Dude, she's still angry." Dean sets the beer on the counter, then opens two and hands one to Cas, saying, "No, drink it. It's the brand you like," when Cas tries to wave it off.

"There's no brand I _like_."

"It's the brand you said tasted less like molecules," Dean insists. He sits across from Cas and gives the bottle a nudge; Cas takes a sip and only wrinkles his nose a little. "Look, her life has been pretty fucked up. You've gotta give her some time to forgive and forget."

"I don't expect her to forgive. I just -- she blames herself, and I -- "

"Did you read her mind? I've told you, you can't just -- "

"I wasn't -- I wanted to know if she was healthy, if she'd been treated well at the group home." Cas drinks some of his beer, probably so he doesn't have to look Dean in the eye, taking long swallows that pull at the line of his throat. "She believes this is her fault -- that if she'd been a better daughter, Jimmy would've have prayed for a sign and her mother wouldn't have run off in the middle of the night."

"Fuck," Dean says, rubbing his hand over his face. "If anything, Jimmy is my fault. You only jumped in his skin because I summoned you. And her mom -- some people just go off the rails after a possession. It's a lot to deal with."

"I know." Cas fiddles with his beer bottle, scratches the stag on the label with his thumbnail. "How do I explain that to her?"

"You can't."

"Dean, I -- "

"Hey, I'm not telling you to give up on her," Dean says. Sam mumbles in his sleep, the bed creaking as he rolls over, and Dean lowers his voice so they don't wake him up. "You just -- don't expect her to believe it. You might have to let her -- you know."

"Yes," Cas says quietly. "I know."

 

+

 

They end up hunting the whole way home: vamps in Utah, a shifter in Colorado, more vamps in Texas, a pair of ghouls in Oklahoma. 

Each time, Dean shoots too much, stabs too much, waits too long to wash the blood from his hands. 

The Mark flares and burns on his arm, white-hot and furious and alive.

 

+

 

A bloodless body in Missouri turns out to be a pair of vetalas instead of a nest of vamps; Sam recognizes the bite patterns once the coroner stops stalling. They track them back to an abandoned warehouse by the river; inside, two guys are tied to a pipe jutting from the wall, sprawled between broken crates and rusty tools. The metallic smell of their blood is nearly buried by the stench of garbage and stale water.

The vetalas look up as the door creaks open, snarling, one of them still hunched over his victim, blood around his mouth. Dean pulls his silver knife, but Cas shouts, "Close your eyes," and kills both of them at once with a brilliant flash of light.

The bodies shrivel as they collapse to the floor, smoke curling up from the holes in their chests. The Mark throbs on Dean's arm, and his hand shakes, his fingers white-knuckled around the handle of his knife.

 

+

 

Cas heals both victims' bite marks and blood loss and exhaustion, a weird chill sweeping through the warehouse as he brushes his fingers over their foreheads.

"I'll drive them home," Sam says, looking tired as he hands Cas a tarp. He has a smudge of dirt on his sweaty cheek. "You guys get these things wrapped up."

Dean rounds on Cas as soon as the Impala rumbles away from the warehouse. The Mark has gone quiet, but his hands are still shaking and his heart is hammering in his chest. He feels empty, hungry. Unsatisfied.

"You shouldn't be wasting your grace like that."

"Healing isn't overly taxing," Cas says, spreading the tarp beside the vetalas. "Are you going to help me with this?"

"That's not what I'm talking about. You" -- Dean waves his left hand around; his right is still gripping his knife -- "we could've killed these guys without a light show."

Cas shrugs one shoulder, the gesture stilted but still very human. "It's not a matter of waste. Until it starts to fail, my grace can't be used up." He turns suddenly, pushing Dean back against the wall and shoving his hand up underneath Dean's jaw. "Besides," he says quietly, "that's not why you're upset. You wanted to kill those vetalas yourself."

"Cas," Dean says, squirming. His dick is filling and he wants to keep it away from Cas' hip. "Let me go."

"No. If I hold you in one place you might actually talk to me." With his free hand, Cas tugs the knife from Dean's grasp; it hits the concrete floor with a bright clang. "You've been quiet recently. Taciturn. Easily angered. Last week, you yelled at your brother for twenty minutes because he forgot to take out the trash. Yet when I ask, you insist you're fine." He slides his hand up Dean's arm, presses his palm against the Mark. "Please, tell me how you feel."

Dean closes his eyes, fists his hand in Cas' sleeve. He forgets how strong Cas is sometimes; it's been years since Cas has used it against him.

"Let me help you," Cas says, his mouth nearly brushing Dean's jaw. "Talk to me. Does the Mark burn when you kill?"

"Yes."

"And when you think about killing?"

"I -- sometimes, yeah."

"When I killed the vetalas, were you angry?"

"Yeah," Dean admits, heat rushing to his face, a sickly mixture of shame and rage. "I wanted to do it. I could already feel it -- pushing the knife in, watching the blood run out, but you did it before I" -- he gasps as Cas leans in a little, as Cas' hip nudges against his dick.

He closes his eyes again, listens to the dull scrape of his heel butting against the wall, the slow drip from one of the broken pipes. His face is on fire, and he feels jittery, like his blood is restless under his skin. It's been a long half-hour of almosts and his body is tired of his brain's mixed signals -- he wanted to kill the vetalas but couldn't; he wants to punch Cas in the face almost as much as he wants to kiss him. Not that it matters; Cas is holding him just tight enough that he'd probably just snap his own neck if he tried to do either.

Cas makes a soft noise, and he loosens the hand under Dean's jaw, slides it down until it's resting at the hollow of Dean's throat. He shifts closer, his lips brushing the corner of Dean's mouth, and -- Christ. He's hard, too. His dick rubs against Dean's, slow; Dean shivers, rolls into it before he can stop himself. 

And he needs to stop himself. Cas doesn't know what he's offering; Dean is practically a monster, and -- 

"That's not true," Cas says, sliding his other hand away from the Mark and holding it at Dean's hip. 

"Stop reading my mind."

"It wasn't intentional. When your thoughts are forceful I can't always avoid them." Cas noses at Dean's jaw, all stubble and warm breath. "As I said, it's not true. You aren't a monster, and I do know what I'm offering."

"Cas."

"I really am incredibly old," Cas says. He kisses Dean, just a quick press of lips, and Dean catches himself chasing Cas' mouth when he pulls away. "In all that time, I've never wanted and loved anything as much as I want and love you."

 

+

 

Dean feels like a teenager, shaky and desperate and already close to coming even though he's barely been touched. Cas works a thigh between his, presses up until it rubs against Dean's dick, and Dean doesn't know what's hotter -- that, or the feel of Cas' dick pushing against his hip, or the noises Cas is making into his mouth. Cas kisses him, fast and sloppy and wet, brushes his fingers over the hollow of Dean's throat, then slides his hand down to Dean's hip, pins him against the wall.

The pressure is perfect, slow but steady, heat flaring low in Dean's gut, sparking under his skin. He drags his mouth down the line of Cas' jaw, bites the skin below Cas' ear as Cas rocks against him. He knots his fingers in Cas' hair, tugging a little, moaning when Cas slides a hand over his ass, when he hitches one of Dean's legs around his thigh.

It opens Dean up, gives Cas enough room to move in closer, shifting until their dicks are lined up, riding against each other. He wants to get Cas' dick out of his pants, feel it in his hand, hard and hot, probably sticky-wet with precome, but there isn't enough space, and Cas is panting into the curve of his neck, and Dean can't stop clutching at Cas' shoulders, digging his fingers into the fabric of Cas' coat.

His orgasm hits him like a punch to the gut, leaves him winded, unable to breathe. Cas comes just a few seconds later, his mouth open against Dean's skin, and the noise he makes is filthy and honest, completely shameless.

 

+

 

"We'll need to find a balance," Cas says about an hour from the bunker, in the boring stretch of US 36 between Belleville and Lebanon. 

"A balance for what?" Sam asks.

"The Mark," Cas says, the leather in the back creaking as he leans closer to Dean's seat. He rests his hand on Dean's shoulder, and Dean finds he likes it there, enough that he ignores the smile twitching at the corner of Sam's mouth. "If he stops killing -- or doesn't kill enough -- he will die and awake as a demon."

"But if he kills too much, we'll lose him."

Cas squeezes Dean's shoulder a little, hooks his thumb in the collar of Dean's shirt. "Yes. If the Mark is fed to satisfaction it will consume him. He will become like a demon -- as close as someone can come without death."

"Balance," Sam says, whistling through his teeth. "Okay, yeah. We'll figure something out."

"Hey, assholes," Dean snaps. "Stop talking about me like I'm not here."

 

+

 

They hunt.

Dean kills a wraith in Omaha and a kitsune in Kansas City, watches as Cas and Sam kill a pair of ghouls at a derelict cowboy cemetery outside of Houston. They track a nest of vampires to an abandoned house in the suburban sprawl between Phoenix and Glendale; there are nine of them, but Cas only lets Dean kill four, and he kisses Dean long and slow against the Impala afterward, cradling Dean's hot face in his hands as he pushes his tongue into Dean's mouth, as the heat and rage in the Mark starts to ebb away.

"So, this is your plan?" Dean asks one night, after a demon ambush that almost went sideways. There had been two of them, waiting in the motel parking lot when Sam and Dean and Cas walked out to the car; Cas had smote both of them, quickly, but the Mark had raged at the loss of prey, filling Dean with an anger so deep and endless it had left him snarling, had kept him jumping out of his skin well after Cas dragged him back inside the motel and blew him against the bathroom door.

"What?" Cas thrusts up a little, sliding his hands up Dean's thighs, and Dean gasps as Cas' dick pushes deeper inside him, fills him up. 

"This." Dean rolls his hips; underneath him, Cas shivers and arches off the bed. "You're just gonna fuck Cain's bad mojo away?"

"It's not the worst thing I could've tried," Cas says, pulling Dean down for a kiss. "Besides, it seems to be working."

 

+

 

Cas falls asleep on a drive home from Idaho; he wakes up at a Pocatello truck stop with a pale face and shadows under his eyes. 

"Oh," he says tonelessly.

Dean feels sick, his breakfast heavy in his gut. "Yeah."

 

+

 

They track a shifter through the Texas Panhandle, corner it just north of Amarillo in Stinnett. The plan is for Sam to kill it -- Dean killed two Djinn last week and Cas' grace has finally started to rot -- but Dean gets separated from the group while trying draw it from its lair and when he turns around he finds the thing staring him in the face.

He shoots it once, twice, three times. Then he drops his gun and pulls his knife, crouching over the body so he can stab it again and again and again and again and again and -- 

"Dean, that's enough."

Dean slumps over, shuddering as he tries to catch is breath. The knife clatters to the floor; Cas brushes his fingers through Dean's hair, then leans down and presses a kiss to Dean's temple.

"Don't." Dean pulls away; he has blood on his hands. He shouldn't touch Cas with all this blood on his hands. "You can't -- I'm not -- "

"No," Cas says, tracing the line of Dean's jaw with his thumb. "When you think you don't deserve it is when you need it most."

 

+

 

Dean loses it after an exorcism in Duluth; demons seem to key the Mark up the most, and it seethes as all that black smoke curls toward the ceiling and out the window, as the dead meatsuit collapses to the floor. All he smells is sulfur and ash.

He punches Sam in the back of the head, elbows Cas in the jaw. Sam staggers back and slumps into the wall, but Cas barely moves, still has enough grace to stand his ground.

"Dean, stop it."

He swings at Cas again, misses because Cas' grace makes him faster. Everything goes quiet. Then he hears something move behind him, and he whirls around just in time to sink his fist into Cas' gut. 

"Dean, this isn't you," Cas says, batting Dean's hand away.

Dean's rage is a living thing, crawling up into the back of his throat, buzzing just underneath his skin. Cas' face is jarringly familiar -- he has kissed that mouth, stroked that jaw, buried his hands in that hair -- but all he cares about is blood and bone. He wants to leave bruises on Cas' skin, wrap his hands around Cas' throat.

"Dean," Cas says again, louder. Dean backs him into a corner, but Cas manages to catch his wrists, holding his arms at his sides in an iron grip. He growls, trying to jerk away, but Cas just turns them, putting Dean against the wall. "Listen to me, this isn't you."

"I'm gonna kill you."

"You can't hurt me."

"You can't keep me like this forever," Dean snarls. He rolls his shoulders, trying to buck away from the wall, but Cas leans in and pins him in place with his hip. "Your juice is running out."

"My... juice will last another three months if I'm careful," Cas says patiently. "You'll come back to yourself long before it runs out."

"Let me go." 

"Dean, please. Remember who you are." Cas presses his mouth to Dean's cheek, to the corner of his jaw. "Remember what you mean to me. To your brother."

"Both of you can go to hell."

"Both of us have been to hell. So have you."

"Shut the fuck up."

"Dean." Cas kisses his mouth, just a soft flutter of lips, so fast that Dean doesn't have time to knock their heads together or break Cas' nose with his jaw. "You are strong enough to fight this. Remember who you are."

"Maybe I don't want to," Dean spits. The anger has started to ebb away, but Dean clings to it, unwilling to let it go. It would be easier like this, to go back to that place where he didn't care about anything; he wouldn't have to hate himself for all the things he's done, wouldn't have to worry about disappointing Cas, hurting Sam. "Maybe I want you to fuck off."

Cas kisses him again, longer and slower, makes a soft noise when Dean leans into it, makes it filthy and wet. He sucks Cas' lip into his mouth, then bites until the copper-tang of blood bursts across his tongue. It's a tiny cut, already healing when Dean pulls away.

He looks at Cas -- really looks at him -- and the rage leaves him in a furious rush, deserting him so quickly his legs buckle and his head swims. Cas catches him under the arms, then pulls him upright and wraps him in a hug.

"I'm sorry," Dean mumbles, hiding his face against Cas' neck. "I'm so sorry, I -- "

"I know," Cas says. He strokes his hand through Dean's hair, then slides it down to his jaw.

Dean feels an icy-hot jolt of grace, stronger than anything Cas has every used to heal. He figures this is it, that Cas is doing what Dean made him promise; he grits his teeth against the pain, hisses "I love you," just before the lights go out.

 

+

 

Dean wakes up handcuffed to his bed. That's too kinky for heaven and not kinky enough for hell, which means -- 

"You lying sonofabitch."

Cas sits on the edge of the bed, the mattress groaning as his hip bumps against Dean's. "I never lied."

"I asked you to kill me, and you -- you said you'd do it. You promised."

"I promised I would deal with it," Cas says. He looks terrible, but Dean can tell if it's from grace-sickness or worry. "I _am_ dealing with it."

"So -- what? You're going to keep me chained to this bed forever?"

"No. I'm going to give you my grace."

Dean leans up on his elbows; that's as far as he can move. "What?" 

"Cain's curse is a manifestation of pure evil. My grace should be enough to neutralize it."

"No. No way." Dean takes a deep breath, clears his throat. He'll never know what he did to deserve this -- to deserve _Cas_. "You'll die."

"I won't die. I'll become human."

"What -- human? You -- you can't want that. You'll -- "

Cas kisses Dean again, so slow and sweet Dean is breathless when he pulls away. Then he unlocks the handcuffs, urging Dean to sit up. 

"This grace is leaving me," Cas says. He slides his hand into Dean's, strokes his thumb over Dean's knuckles. "I can let it kill me, or I can cut it out of me before the damage becomes to severe." 

"You could go back to heaven," Dean argues, his voice sticking in his throat. "They could -- "

"It's not something that can be fixed. Yes, if I returned to heaven, I would stop growing sicker. But I wouldn't heal. I would remain exactly as I am now, less than half an angel."

"Better than being human."

Cas shakes his head. "I already told you, I want and love you more than I've ever wanted or loved anything. If I returned to heaven I would have to stay there. I would never see you again." 

"Damn it, Cas."

Cas reaches past him, pulls an angel blade out from under the pillow. He holds it out to Dean, then lifts his chin, gesturing to a mark on his throat, drawn in ballpoint pen. 

"Right there. A quarter-inch deep."

"Cas, I -- um." Dean's hand is shaking; on the inside of his arm, the Mark is beating like a drum. "Maybe Sam should do it."

"I trust you," Cas says simply.

Dean slides his left hand around the back of Cas' neck, holds the angel blade close to the tip so he isn't tempted to ram it through Cas' throat. Cas hisses when Dean nicks his skin; the grace puffs out first, curling like a cloud of smoke, then blood, so much blood, and Dean wants to touch it, run his fingers through it, get -- "

"Breathe it in," Cas hisses. "Breathe it in before it escapes."

Dean sucks it in all at once, shivering as it sinks in, pulsing bright and icy-hot through his blood, and -- Christ. It's too much. He can feel everything, hear everything, smell everything. He wants to close his eyes and cover his ears, crawl underneath the bed where it's quiet and dark.

"You have to heal me," Cas says, his voice thin around the edges. "Quickly, before it fades into the Mark."

"I don't know how."

Cas grabs his hand, presses it to the blood welling from his throat. "You can do it. Just picture it -- the vessels healing, the skin knitting, the" -- he slumps over, his mouth going slack and his eyes sliding closed.

"Fuck." 

Dean closes his eyes, fumbles for the strange heat thrumming inside him. He can't grab it, can't control it, until suddenly he is, until he's holding it like it's sitting in the palm of his hand. He thinks about the cut on Cas' throat, blood and tissue and skin, and the grace crests inside him, spilling out into Cas in a furious rush. 

"Stop -- Dean, you have to stop," Cas says, tugging on Dean's wrist. "You have to save it for the Mark or it won't be enough."

"You gave it to me," Dean says, pulling him into a hug. "It'll be enough."

 

+

 

A sharp pain stabs through his arm, so hot it feels like his blood is on fire.

 

+

 

When Dean wakes up again, he has a splitting headache and a dry mouth. The grace is gone, and the inside of his arm is smooth, unscarred.

"Go back to sleep," Cas mumbles. He pulls Dean back against his chest, kisses the place where Dean's neck curves into his shoulder.


End file.
